/*
 * Copyright 2019-present HiveMQ GmbH
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.hivemq.persistence.local;

import com.hivemq.extension.sdk.api.annotations.NotNull;

import java.util.function.Consumer;

public class DeltaCounter implements Runnable {

    private final @NotNull Consumer<Long> consumer;
    private long delta;

    private DeltaCounter(final @NotNull Consumer<Long> consumer) {
        this.consumer = consumer;
    }

    public static @NotNull DeltaCounter finishWith(final @NotNull Consumer<Long> consumer) {
        return new DeltaCounter(consumer);
    }

    public void increment() {
        delta += 1;
    }

    public void decrement() {
        delta -= 1;
    }

    @Override
    public void run() {
        consumer.accept(delta);
    }
}
